Recently there have been various glasses-type video display devices in which video displayed on a display device such as a Liquid Crystal Display (LCD) is observed as a virtual image enlarged through an optical system having an eyepiece, a half mirror, or the like. The glasses-type video display devices are called a head-mounted display. For example, WO2004/061519A1 (Patent Document 1) discloses a head-mounted display.
FIG. 1 shows an example of the head-mounted display. In the head-mounted display 1, two headphone housings 2 are connected by a rear arm 3. The rear arm 3 has resilience. In mounting the head-mounted display 1, the headphone housings 2 are located at ear positions, and the human head (ear portions) is caught in a space between the headphone housings 2 by the resilience of the rear arm 3, thereby fixing the head-mounted display 1. That is, the headphone housings 2 are a fixing portion, and the rear arm 3 is a connection portion. As shown in FIG. 1, the head-mounted display 1 is mounted at a position such that the rear arm 3 is orientated toward the back of the head.
A display unit arm 4 is turnably attached to one of the headphone housings 2 with a support portion 5 interposed therebetween, and the display unit arm 4 is slidable back and forth. Turning the display unit arm 4 enables motions of a vertical swing and a level swing. A display unit 7 is attached in a leading-end portion of the display unit arm 4 with a display unit hinge 6 interposed therebetween, and the display unit 7 displays the video on an eye of a user. The display unit 7 can perform motions of yaw, roll, and pitch relative to the display unit arm 4 by action of the display unit hinge 6.
In use, as shown in FIG. 1, the display unit arm 4 is turned, the position in the back and forth direction of the display unit arm 4 is adjusted, and the display unit 7 is rotated about the display unit hinge 6, such that the display unit 7 is located in front of an eye of the user to display the video.
However, because usually an upper portion is larger than a lower portion in a human head shape in ear portions, the headphone housings 2 are obliquely worn as shown in FIG. 2 when the headphone housings 2 are worn in the ear portions. When the display unit arm 4 is attached to one of the headphone housings 2 so as to be kept level at the position where the headphone housings 2 are orientated toward the vertical direction, it is necessary that the display unit 7 be kept level by bending the display unit hinge 6, because the display unit arm 4 is inclined (in such a way that a user side is higher while the outside is lower) in wearing as shown in FIG. 2. Therefore, there arises a problem that a well-balanced appearance cannot be realized while adjustment of the display unit 7 is complicated.
In view of the foregoing, a problem to be solved by the present invention is to provide a video display device which realizes the well-balanced appearance without complicating the adjustment of the display unit.